The present invention relates to optical scanners and more specifically to a multiple source optical scanner.
Optical scanners are well known for their usefulness in retail checkout and inventory control. Optical scanners generally employ a single laser source, the light from which is collimated and focused to produce a scanning beam. They may additionally employ a mirrored spinner to direct the beam against a plurality of stationary mirrors, and a detector to collect the beam after it is reflected by a bar code label. The pattern produced by such a scanner is characterized by lines oriented at various angles to one another.
Optical scanners require as large a depth of field as possible to minimize the accuracy with which articles must be located over the scanners. Unfortunately, the beam from a single laser source has a limited depth of field due to the nature of light.
Optical scanners also require as dense a scan pattern as possible in order to maximize the chances of a scanner reading a bar code.
Therefore, it would be desirable to provide an optical scanner which produces a pattern density and a depth of field greater than those of single laser source scanners.